<template>
  <div class="login_container">
      <div class="login_box">
          <!-- 头像区域 -->
          <div class="avatar_box">
              <img src="../assets/logo.png" alt="">
          </div>
          <!-- 登录表单区域 -->
        <el-form ref="loginFormRef" :model="loginForm" :rules="loginFormRules" label-width="0px" class="login_form">
              <!-- 用户名 -->
            <el-form-item prop="username">
              <el-input v-model="loginForm.username" prefix-icon="el-icon-user-solid"></el-input>
            </el-form-item>
            <!-- 密码 -->
            <el-form-item prop="password">
              <el-input type="password" v-model="loginForm.password" prefix-icon="el-icon-edit"></el-input>
            </el-form-item>
          <!-- 按钮区域 -->
            <el-form-item class="btns">
              <el-button type="primary" @click="login">登录</el-button>
              <el-button type="info" @click="resetLoginForm">重置</el-button>
            </el-form-item> 
        </el-form>  
      </div>
  </div>  
</template>

<script>
export default {
    data(){
        return{
            //登录表单的数据绑定对象
            loginForm:{
                username:"admin",
                password:"123456"
            },
            //表单的验证规则对象
            loginFormRules:{
              username:[ 
                 { required: true, message: '请输入用户名', trigger: 'blur' },
                 { min: 3, max: 10, message: '长度在 3 到 10 个字符', trigger: 'blur' }
              ],
              password:[
                 { required: true, message: '请输入用户名', trigger: 'blur' },
                 { min: 6, max: 15, message: '长度在 6 到 15 个字符', trigger: 'blur' }
              ]
            }
        }
    },
    methods:{
        //点击重置登录表单
        resetLoginForm(){
           this.$refs.loginFormRef.resetFields();
        },
        login(){
            this.$refs.loginFormRef.validate(async valid=>{
            if(!valid) return;
            const {data:res} = await this.$http.post('login',this.loginForm);
            if(res.meta.status !== 200)
              return this.$message.error('登陆失败');
              this.$message.success('登陆成功'); 
              //1.将登陆成功之后的token保存到客户端的sessionStorage中
                //1.1 项目其他api接口只有登录成功后才能访问
                //1.2 token只应在当前网页打开期间生效，所以保存到sessionStorage中 
                  window.sessionStorage.setItem('token',res.data.token);
              //2.通过编程式导航跳转到后台主页，路由地址为 /home
              this.$router.push('/home') 
            });
        }
    }
}
</script>

<style Lang="less" scoped>
   .login_container{
       background-color: #2b4b6b;
       height: 100%;
   }

   .login_box{
       width: 450px;
       height: 300px;
       background-color: #fff;
       border-radius: 3px;
       position: absolute;
       left: 50%;
       top: 50%;
       transform: translate(-50%,-50%);
   }

   .avatar_box{
       height: 130px;
       width: 130px;
       border:1px solid #eee;
       border-radius: 50%;
       padding: 10px;
       box-shadow: 0 0 10px #ddd;
       position: absolute;
       left: 50px;
       transform: translate(100px,-50%);
       background-color: #fff;
   }

    img{
           width: 100%;
           height: 100%;
           border-radius: 50%;
           background-color: #eee;
       }

       .login_form{
           position: absolute; 
           bottom: 0;
           width: 100%;
           padding: 0 20px;
           box-sizing: border-box;
       }
       
       .btns{
           display: flex;
           justify-content: flex-end;
       }

</style>